>>283233672
A lot of these problems don't have to actually exist.
Yes, some phrases (like hello) could vary by language/culture, but all the gestures could be universalized.
There's no reason, hypothetically from today on, that the Japanese and US gesture for ok be either of the two.
With spoken language, this is unachievable, but all you're doing with sign language is assigning gestures (that anyone can perform) to concepts.
If one day, all the "hearing impaired associations" came together and said;
>from today on, this is the official global sign language, we expect everyone to speak it by the next couple generations
Kids will be taught both versions, and eventually just one.
You'll still have differences, but they'll basically be accents, and distinguishable enough for anyone, anywhere. Much less learning to do than learning basically a whole new language.
It probably would be a logistical nightmare, but it would and is possible. We shouldn't deny that. The only thing that's keeping people from adapting something like this--unlike with spoken languages where there is culture, national identity and much more to learn involved--is laziness and convenience.
That's not to say sign languages do not mirror the culture of the country they are developed in (the bowing example, for one), but they have no concrete rules and, yet again, remain as such due to convenience.
I suppose my stance on this is a "the end justifies the means". kind of one. Imagine how more accessible sign language would be to the whole world, and how much easier it would be for travelling deaf-mute people.
I imagine that people like this want to be just as included in the "normal" world as others, and a new universal, always useful sign language could facilitate more people learning it and including them in their lives.